Automatic electric fire-alarm



(No Model.)

W. A. GUTHRIB. AUTOMATIC ELECTRIC FIRE ALARM.

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UNITED STATES PATENT OEErcE.

WILLIAM A. GUTHRIE, OF DURHAM, NORTH CAROLINA.

AUTOMATIC ELECTRIC FIRE-ALARM.

SPECIFICATION forming part of Letters Patent No. 598,508, dated February 8, 1898.

Application nea July 7, 1897.

To all whom t rtcty concern.-

Be it known that I, WILLIAM A. GUTHRIE, residing at Durham, in the county of Durham and State of North Carolina, have invented certain new and useful Improvements in a Combined Push-Button and Electric Fire- Alarm; and I do declare the following to be a iull, clear, and exact description of my invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

Figure l is a perspective view showing my invention in use. Fig. 2 is a front elevation with the cap removed. Fig. 3 is a cross-sectional view. Fig. 4 is a perspective View.

This invention relates to certain new and useful improvements in combined push-buttons and electrical lire-alarms, the particular object being to provide a device of this character of simple construction, which can be put into use at a small cost and with little labor, and which can be relied upon in its action.

Another object of my present invention is to construct a lire-alarm which shall be cheaper and more suitable for sale than my former patent for an automatic electric firealarm,No.5l4,36l, patented February 6,1894, over which this is a decided improvement.

My invention consists in the novel construction and combination of parts, all as hereinafter described, and pointed out in the appended claim.

Referring to the accompanying drawings, the letter A designates the base of a frame of the ordinary push-button variety, which may be secured by means of screws to the ceiling` of the room or other overhead support at any point desired. i

B B are metal plates secured to the base A by binding-screws, which fasten the wires C O thereto. These wires are connected with a battery and alarm of the ordinary variety used' in such cases.

D represents a spring, preferably constructed of thin flexible sheet metal, which is secured at one end to the plate B' and bent in semicircular shape, so that its outer end is designed to contact with the plate B, and

Serial No. 643,729. (No model.)

thereby the circuit is completed and the alarm is sounded.

E is a line wire, preferably of fusible metal, though it may be of the ordinary non-fusible variety, which is secured to the thinspring D and extends outward through the hole in the cap ofthe frame usually occupied by the pushbutton. Hung loosely by its center upon the bent outer end of this wire and fitting around the hollowed face of the frame is a piece of fusible metalF in the shape of a button. This piece of metal is of sullicient weight to keep the spring D away from the plate B and thereby prevent the circuit from being closed and the alarm from being sounded.

Now the operation of my invention is simple and sure. Vhen the lire occurs, the metal button F fuses and the spring D instantly being` released automatically makes the contact with the plate B, completes the circuit, and

sounds the alarm. If the wire E is also fusible metal, then the fusion of either this wire or the weight F operates to automatically release the spring, complete the circuit, and sound the alarm.

The weight F or the wire E may be made of any of the well-known alloys which fuse at a very low temperature-such as alloys of tin, lead, and bismuth, or tin, lead, bismuth, and cadmium, whose fusing-point is considerably below the temperature of boiling water. Owing to the readiness with which the weight F and wire E fuse, contact with the flame is not necessary for their release, as this will take place upon the increase of temperature to the fusing-point, though the fire may be at some other portion of the apartment.

The bell may be located at any part of the building, and in cases where the dilerent apartments of a large building, such as a hotel, are each supplied with one of the alarms proper communications may be made with an annunciator in the office.

When it is desired, the button may be pressed in the usual manner to make the contact and sound the alarm.

Having thus fully described my invention, what I claim as new, and desire to secure by means of Letters Patent, is-

A combination push-button and automatic electric fire-alarm comprising the base adapted to be secured to the ceiling or other over- IOO head support, a pair of plates and bindingthe hhtton is suspended from the curved exscrews on the under face thereof, one of said tension and holds it out of Contact with the 1o plates having a downwardly-curved extenother plate, substantially as described.

sion normally in Contact With the other, a i push-button of easily-fusible metal below WILLIAM A' GUTHRIE' said curved extension, and a Wire passed Vitnesses: through openings in the curved extension and THOS. L. PEAY, the button and having bent ends, whereby WM. B. GUTHRIE. 

